The present invention relates to improvements in apparatus for accumulating arrays of rod-shaped articles, especially for accumulating cigarettes, cigars or cigarillos into arrays which resemble parallelepiped blocks and are ready for introduction into packets or analogous containers. More particularly, the invention relates to improvements in apparatus which can be utilized with advantage in packing machines for cigarettes or analogous rod-shaped articles (hereinafter called cigarettes for short) as a means to transfer from the ducts of a magazine discrete layers of cigarettes for introduction into packets or into hollow receptacles preparatory to the making of envelopes around successively filled receptacles or preparatory to the transfer of arrays from such receptacles into prefabricated packets or into the hollow mandrels of a turret or an analogous conveyor.
It is already known to accumulate multi-layer arrays of cigarettes by resorting to a magazine with several groups of ducts wherein each group of ducts serves to accumulate a succession of layers of parallel cigarettes. Reference may be had to commonly owned patent application Ser. No. 188,255 filed Sept. 19, 1980 by Otto Erdmann, now U.S. Pat. No. 4,362,235 granted Dec. 7, 1982. For the sake of convenience, the disclosure of this patent is incorporated herein by reference. The apparatus of Erdmann utilizes a magazine with three groups of ducts which form successive layers of cigarettes at three different levels, and such layers are thereupon transferred into successive receptacles of an intermittently advancing conveyor which moves successive receptacles to positions of register with successive groups of ducts. Pushers or analogous transfer devices are used to expel the lowermost layers of cigarettes from the corresponding groups of ducts and into the registering receptacles so that each receptacle which advances beyond the last group of ducts contains three superimposed layers of cigarettes, normally in the customary quincunx formation including a lowermost layer of seven parallel cigarettes, a median layer of six parallel cigarettes which are staggered with reference to the cigarettes of the lowermost layer, and an uppermost layer of seven parallel cigarettes which are staggered with reference to the cigarettes of the median layer.
The apparatus of Erdmann further employs stationary guides which confine the cigarettes of successive layers during transfer into the registering receptacles. The guides are disposed at different levels so that they engage the respective layers from above during expulsion of the layers from the respective groups of ducts and into the adjacent receptacles of the intermittently advancing conveyor. The difference between the levels of the guides cooperating with successive groups of ducts equals or approximates the diameter of a cigarette.
An advantage of apparatus wherein arrays of, for example, twenty cigarettes each are formed in several stages (i.e., wherein each array is assembled of discrete layers rather than by simultaneous expulsion of an entire multi-layer array from the magazine of a packing machine) is that the assembly of arrays from discrete layers which are introduced into a receptacle during successive periods of dwell of the conveyor takes up much less time than the accumulation of complete multi-layer arrays in and the transfer of complete arrays from the magazine. The savings in time are attributable to the fact that the accumulation of a layer of cigarettes by gravity takes up but a small fraction of time which is required to accumulate by gravity flow a full multi-layer array of cigarettes. Savings in time are especially desirable in modern high-speed cigarette packing machines each of which can consume the output of at least one cigarette maker or filter tipping machine.
However, heretofore known apparatus which accumulate arrays of cigarettes by assembling such arrays at the rate of one layer at a time also exhibit a serious drawback. Thus, the cigarettes which are disposed in the receptacles of and are moved sideways by the intermittently advancing conveyor are subjected to pronounced acceleration and deceleration tending to move the cigarettes from optimum positions with reference to each other. This is particularly felt in a modern packing machine which must accumulate several hundred multi-layer arrays per minute. While such rapid stepwise advances of the conveyor need not appreciably influence the positions of cigarettes in the fully assembled arrays, abrupt acceleration and deceleration of receptacles which are only partially filled with cigarettes is highly likely to result in at least some undesirable changes in orientation of cigarettes which together constitute less than a full array, i.e., which do not as yet completely fill the respective receptacle. Such changes in orientation can prevent the admission of the last layer of cigarettes and necessitate an interruption of operation with attendant huge losses in output.